Photographic materials and processes

ABSTRACT

Light-sensitive photographic silver halide emulsions and elements are provided which feature converted-halide silver halide grains in which the halide consists of at least 50 mole percent bromide and up to 10 mole percent iodide, any remaining halide being chloride; the surface of said grains being chemically sensitized; and, said silver halide grains having contiguous thereto a photographic color coupler. Processes for producing photographic color images are also provided wherein emulsions and elements of the type described above, after exposure, are reacted with an aromatic primary amino color developing agent to form a dye image.

United States Patent [72] Inventor Francis J. Evans Rochester, N.Y. 211Appl. No. 21,469 [22] Filed Mar. 20, 1970 [45] Patented Nov. 23, 1971[73] Assignee Eastman Kodak Company Rochester, N.Y.

[54] PHOTOGRAPHIC MATERIALS AND PROCESSES 24 Claims, No Drawings 52 0.5.CI 96/22, 96/55, 96/74, 96/84 [51] lnt.Cl G03c 7/00, G03c 5/44, G03c H84[50] Field of Search 96/69, 74, 94, 84, 70, 22

[56] References Cited UNITED STATES PATENTS 2,490,751 12/1949 Hanson,Jr... 96/69 2,322,027 6/1943 .Ielley et aI. 96/97 PrimaryExaminer-Norman G. Torchin Assistant ExaminerAlfonso T. Suro PicoAtlorneys-W. H. J. Kline, .l. R. Frederick and O. H. Webster ABSTRACT:Light-sensitive photographic silver halide emulsions and elements areprovided which feature converted-halide silver halide grains in whichthe halide consists of at least 50 mole percent bromide and up to 10mole percent iodide, any remaining halide being chloride; the surface ofsaid grains being chemically sensitized; and, said silver halide grainshaving contiguous thereto a photographic color coupler. Processes forproducing photographic color images are also provided wherein emulsionsand elements of the type described above, after exposure, are reactedwith an aromatic primary amino color developing agent to form a dyeimage.

PI-IOTOGRAPIIIC MATERIALS AND PROCESSES This invention relates tophotographic materials and processes, and more particularly tophotographic materials and processes for producing color images.

It is well known in the art to provide photographic elements whichfeature blue-, greenand red-sensitive silver halide emulsion layerswhich are adapted to form, respectively, yellow, magneta and cyan dyeimages. A typical photographic element of this type is described inVanCampen et al. US. Pat. No. 3,416,923 issued Dec. 17, 1968, column 2,lines 20-29. While such elements provide good multicolor photographicrecords, it would be desirable to provide improved photographic elementswhich exhibit increased storage stability, higher speed, lower fog, amore satisfactory sensitometric curve shape, increased developabilityand better resistance to pressure sensitivity.

Accordingly, it is one object of this invention to provide photographicemulsions and elements which contain a photographic color coupler, andwhich exhibit good storage stability.

Another object of this invention is to provide photographic emulsionsand elements which contain a photographic color coupler, and whichexhibit good photographic speed.

Still another object of this invention is to provide photographicemulsions and elements which contain a photographic color coupler, andwhich produce low fog.

A further object of this invention is to provide photographic emulsionsand elements which contain a photographic color coupler, and whichproduce excellent sensitormetric curve shapes.

Still another object of this invention is to provide photographicemulsions and elements which contain photographic color couplers, andwhich exhibit good developability.

Still another object of this invention is to provide photographicemulsions and elements which contain photographic color couplers, andwhich exhibit high gamma.

Another object of this invention is to provide photographic emulsionsand elements which contain a photographic color coupler, and which havehigh resistance to pressure sensitivity.

Still another object of this invention is to provide processes forforming dye images in photographic emulsions and elements of the typedescribed herein.

Other objects of this invention will be apparent from the disclosureherein and the appended claims.

In accordance with one embodiment of this invention, a light-sensitivephotographic emulsion is provided comprising converted-halide silverhalide grains, the halide of said grains containing at least 50 molepercent bromide and up to mole percent iodide, any remaining halidebeing chloride; the surface of said grains being chemically sensitized;and, said emulsion containing a photographic color coupler.

In another embodiment of this invention, photographic elements areprovided comprising a support having coated thereon at least onelight-sensitive photographic emulsion layer comprising converted-halidesilver halide grains; the surface of said grains being chemicallysensitized; and, said emulsion layer having a photographic color couplercontiguous to said silver halide grains.

In another embodiment of this invention, photographic elements areprovided comprising a support having coated thereon at least threesuperposed hydrophilic colloid layers containing light-sensitive silverhalide grains, said layers being differentially sensitive to red, greenand blue radiation, said layers having contiguous to the silver halidethereof, respectively, cyan, magenta and yellow dye-forming photographiccolor couplers; the silver halide grains in at least one of said silverhalide emulsions being convertedhalide silver halide grains; and, thesurface of said converted-halide grains being chemically sensitized.

ln.a preferred embodiment of this invention, a photographic element isprovided comprising a support having coated thereon at least threesuperposed hydrophilic colloid layers containing light-sensitive silverhalide grains, and layers being differentially sensitive to red, greenand blue radiation, said layers having incorporated therein,respectively, cyan, magenta and yellow dye-forming photographic colorcouplers; the light-sensitive silver halide in each of said layerscomprising converted-halide silver halide grains; and, the surface ofsaid grains being chemically sensitized. Particularly good results areobtained when the green-sensitive silver halide emulsion layer is coatedbetween the redand blue-sensitive silver halide emulsion layers, and theblue-sensitive layer is coated adjacent the support. A hydrophiliccolloid layer containing ultraviolet absorber is advantageously employedbetween the red-sensitive and green-sensitive silver halide emulsionlayers.

In still another embodiment of this invention, color images are providedin the exposed photographic elements described herein by developing saidexposed photographic element with an aromatic primary amino colordeveloping agent which reacts with the photographic color coupler in thephotographic element to form a dye. Silver halide and silver image isremoved from the element in any convenient manner, such as by fixing andbleaching.

The photographic emulsions and elements in accordance with thisinvention feature excellent storage stability, good speed, low fog,excellent sensitometric curve shape, good developability and highresistance to pressure sensitivity. The chemically sensitizedconverted-halide silver halide grains employed herein generally aresuperior to corresponding chemically sensitized conventional negativesilver halide emulsions with respect to storage stability, speed, fog,sensitometric curve shape, developability and resistance to pressuresensitivity.

The converted-halide silver halide grains employed in the practice ofthis invention have a halide content of at least 50 mole percent, andpreferably at least mole percent bromide, and contain up to 10 molepercent, and preferably less than 5 mole percent iodide, any remaininghalide being chloride. Especially good results are obtained with silverhalide grains containing about mole percent bromide and about 10 molepercent chloride.

The term converted-halide silver halide grains" is employed herein as aword of art and denotes silver halide grains prepared by forming anemulsion of silver salt grains consisting at least partly of a silversalt more soluble in water than silver bromide, and converting at leasta portion of such grains to silver bromide or silver bromoiodide salts.

More specifically, such silver halide grains can be prepared by forminga silver salt which is (l) more soluble in water than silver bromide,and (2) has a solubility of less than about 0.02 grams, and preferablyless than about 0.00002 grams per millilters of water at 20 C. Usefulsalts more soluble than silver bromide include silver chloride, silverthiocyanate and silver citrate. Such salts are conveniently formed byadding separate solutions of silver nitrate in water, and a suitableaqueous alkali metal salt solution, such as potassium chloride,potassium citrate or potassium thiocyanate, to an aqueous gelatinsolution containing a small amount of the alkali metal salt. The firsttwo solutions are preferably added slowly to the aqueous gelatinsolution. The temperature of all the solutions is preferably maintainedbetween about 20 and 50 C. After the formation of the silver salts moresoluble than silver bromide, a suitable bromide salt can be added toconvert at least part of the more soluble silver salt to silver bromide.If desired, a suitable iodide salt can also be added to form silverbromoiodide. Potassium bromide and potassium iodide are especiallyuseful for this purpose. When silver chloride is used as the silver saltmore soluble than silver bromide, it is not essential to convert all thechloride to bromide or bromoiodide, nor is it essential that the silverhalide grains contain iodide. The useful silver halide grains thusinclude silver bromide; silver bromoiodide; silver chlorobromide; and,silver chlorobromoiodide. The method for preparing emulsions of the typeemployed in this invention is described by Davey and Knott US. Pat. No.2,592,250 issued Apr. 8, I952.

The converted-halide silver halide emulsions described herein have alsobeen referred to by those skilled in the art as "halide conversionemulsions" and halide converted photographic emulsions".

The converted-halide silver halide grains employed in this invention canbe chemically sensitized by any means suitable for this purpose, manymethods having been previously described in the prior art. Chemicalsensitization, as used herein, includes sensitization of the typedescribed by Antoine Hautot and Henri Saubenier in Science et IndustriesPhotographiques," vol. XXVlll, Jan. 1057, pages 1-23 and Jan. 1957,pages 57-65. Such chemical sensitization includes four major classes,viz., noble metal or gold sensitization, sulfur sensitization, such asby a labile sulfur compound, selenium sensitization, such as by a labileselenium compound, reduction sensitization, i.e., treatment of thesilver halide with a strong reducing agent which does not fogappreciably the silver halide but introduces small specks of metallicsilver into the silver halide crystal or grain, or telluriumsensitization. Sulfur and selenium sensitization are the preferredchemical sensitizers in the practice of this invention.

The converted-halide silver halide grains can be chemically sensitizedby any of the accepted procedures. Emulsions containing such grains canbe digested with naturally active gelatin, or sulfur compounds can beadded, such as those described in Sheppard U.S. Pat. No. 1,547,944issued Mar. 2, 1926, Sheppard et al. U.S. Pat. No. 1,623,499 issued Apr.5, 1927 and Sheppard et a1. U.S. Pat. No. 2,410,689 issued Nov. 5, 1946.

The converted-halide silver halide grains can also be treated with saltsof the noble metals, such as ruthenium, rhodium, palladium, iridium, andplatinium, Representative compounds are ammonium chloropalladate,potassium chloroplatinate, and sodium chloropalladite, which are usedfor sensitizing in amounts below that which produces any substantial foginhibition, as described in Smith and Trivelli U.S. Pat. No. 2,448,060issued Aug. 31, 1948, and as antifoggants in high amounts, as describedin Trivelli and Smith U.S. Pat. Nos. 2,566,245 issued Aug. 28, 1951 and2,566,263 issued Aug. 28, 1951.

The converted-halide silver halide grains can also be chemicallysensitized with gold salts as described in Waller et al. U.S. Pat. No.2,399,083 issued Apr. 23, 1946, and Damschroder et al. U.S. Pat. No.2,642,361 issued 16, 1953. Suitable compounds are potassiumchloroaurite, potassium aurithiocyanate, potassium chloroaurate, aurictrichloride and 2-aurosulfobenzothiazole methochloride.

The converted-halide silver halide grains can also be reductionsensitized with reducing agents, such as stannous salts (Carroll U.S.Pat. No. 2,487,850 issued Nov. 15, 1949), polyamines, such as diethylenetriamine (Lowe and Jones U.S. Pat. No. 2,518,698 issued Aug. 15, 1950),polyamines, such as spermine (Lowe and Allen U.S. Pat. No. 2,521,925issued Sept. 12, 1950), or bis(B-aminoethyl) sulfide and itswatersoluble salts (Lowe and Jones U.S. Pat. No. 2,521,926 issued Sept.12, 1950).

Labile selenium can be used to chemically sensitize the convened-halidesilver halide grains used herein, as described in Sheppard U.S. Pat. No.1,623,499 issued Apr. 5, 1927, as well as Sheppard U.S. Pat. Nos.1,574,944 issued Mar. 2, 1926 and 1,602,592 issued Oct. 12, 1926.

Combinations of chemical sensitizers are also useful, such as a noblemetal and labile selenium as described in Dunn U.S. Pat. No. 3,297,446issued Jan. 10, 1967 and Dunn U.S. Pat. No. 3,442,653 issued May 6,1969, or the combination of a noble metal labile selenium and a sulfurcompound as described in McVeigh U.S. Pat. No. 3,297,447 issued Jan. 10,1967.

A mercuric salt can be present during the preparation of theconverted-halide silver halide grains, such as during the formation ofthe silver salt which is more soluble than silver bromide. The mercuricsalt increases the speed and reduces fog. Any mercuric salt can be used,including inorganic mercuric salts such as mercuric sulfate, mercuricacetate, mercuric nitrate or a mercuric halide e.g., mercuric chloride;or, an organic mercuric salt, such as mercuric salts with amines, e.g.,the mercuric amine salts described in Allen et al. U.S. Pat. No.2,728,663 issued Dec. 27, 1955, the disclosure of which is incorporatedherein by reference.

A wide variety of photographic color couplers can be employed in thepractice of this invention. As used herein, the term color couplerincludes any compound which reacts (or couples) with the oxidationproducts of primary aromatic amino developing agent or photographicdevelopment to form a dye. Typical useful color couplers includephenolic, 5- pyrazolone, heterocyclic and open-chain ketomethylenecompounds. Specific cyan, magneta and yellow color couplers which can beused, respectively, in the cyan, magenta and yellow dye-forming units ofthe invention are described in Graham et al. U.S. Pat. No. 3,046,129issued July 24, 1962, column 15, line 45 through column 18, line 51,which disclosure is incorporated herein by reference. Such colorcouplers can be dispersed in the emulsion layers in any convenientmanner, such as by using the solvents and the techniques described inU.S. Pat. Nos. 2,322,027 or 2,801,171. The useful couplers includeFischer-type incorporated couplers such as those disclosed in FischerU.S. Pat. No. 1,055,155, and par ticularly nondiffusible Fischer-typecouplers containing branched carbon chains, e.g., those referred to inthe references cited in Frohlich et al. U.S. Pat. No. 2,376,679, column2, lines 50-60. These elements can be processed by one of the proceduresdescribed in Graham et al. U.S. Pat. No. 2,046,129, columns 23 and 24,or by the development process described by Edens et al. U.S. Pat.application Ser. No. 736,010 filed June 11, 1968, now U.S. Pat. No.3,582,322 and corresponding German Pat. application 1,928,554 whichfeatures a color process in which the color development step is followedwith a blix bath comprising silver halide solvent and an oxidizing agentfor silver. The disclosure of the Edens et al. application isincorporated herein by reference.

The photographic color couplers employed in this invention can bepositioned in photographic elements so that during processing in aqueousalkaline color developing solutions, color developing agent oxidized ondeveloping silver halide in the photographic element reacts with thephotographic color coupler. Accordingly, the photographic color couplerscan be integral with and contiguous to the silver halide by beingincorporated in the silver halide emulsion or in a separate layercontiguous thereto. Also, the photographic color couplers can beseparated from silver halide emulsion layers by layers of a hydrophiliccolloid such as gelatin or a related composition through which oxidizeddeveloping agents can really diffuse in the presence of an aqueousalkaline processing solution.

In color systems of the type useful in this invention, subtractive dyeimages can be generated by a color negative process, such as the processdescribed by W. T. Hanson and W. l. Kesner in an article in the Joumalof the Society of Motion Picture and Television Engineers, Vol. 61(1953) pages 667-701; or, by a color reversal process wherein reversalsilver images are generated from a photographic color coupler, such asby using a direct positive emulsion or using a negative emulsion whichis given an imagewise exposure, developed in a black-and-white developerto provide a negative silver image, and then at least one additionalexposure (or other suitable fogging treatment) followed by additionaldevelopment to generate the desired subtractively colored dye images.

In preferred embodiments of the invention, the photographic elementincludes a hydrophilic colloid layer which contains a suitableultraviolet absorber, U.S. as a benzotriazole, e.g., the phenyl-typecompounds described in Sawdey U.S. Pat. No. 3,253,921 issued May 31,1966 and the thiazolidines of the type described in a number of patentsincluding Sawdey U.S. Pat. NOs. 2,739,971 issued Mar. 27, 1956,2,739,888 issued Mar. 27, 1956 and 3,250,617 issued May 10, 1966. Thislayer can be an overcoat or can be positioned between the redandgreen-sensitive emulsion layers in elements having a support coated, inthe order given, with blue-, greenand red-sensitive emulsion layers.

The multilayer color-producing elements of the invention preferablycomprise blue-, greenand red-sensitive silver halide emulsion layers. Asis well known, silver halide emulsions are typically sensitive to blueradiation, although additional sensitizing dyes absorbing in the blueregion can also be added to modify the sensitivity of the emulsion toblue radiation as desired. Green and red spectral sensitization can beconferred by any of the dyes suggested in the art for this purpose,including those described in Brooker et al. U.S. Pat. No. 2,526,632issued Oct. 24, 1950; Sprague U.S. Pat. No. 2,503,776 issued Apr. 11,1950; Brookeret al. U.S. Pat. No. 2,493,748 issued Jan. 10, 1950; andTaber et al. U.S. Pat. No. 3,384,486 issued May 21, 1968. Spectralsensitizers which can be used include the cyanines, merocyanines,complex (tri or tetranuclear) merocyanines, complex (tri ortetranuclear) cyanines, holopolar cyanines, styryls, hemicyanines (e.g.,enamine hemicyanines), oxonols and hemioxonols. Dyes of the cyanineclasses may contain such basic nuclei as the thiazolines, oxazolines,pyrrolines, pyridines, oxazoles, thiazoles, selenazoles and imidazoles.Such nuclei may contain alkyl, alkylene, hydroxyalkyl, sulfoalkyl,carboxyalkyl, aminoalkyl and enamine groups and may be fused tocarbocyclic or heterocyclic ring systems either unsubstituted orsubstituted with halogen, phenyl, alkyl, haloalkyl, cyano, or alkoxygroups. The dyes may be symmetrical or unsymmetrical and may containalkyl, phenyl, enamine or heterocyclic substituents on the methine orpolymethine chain. The merocyanine dyes may contain the basic nucleimentioned above as well as acid nuclei such as thiohydantoins,rhodanines, oxazolidenediones, thiazolidenediones, barbitun'c acids,thiazolineones, and malononitrile. These acid nuclei may be substitutedwith alkyl, alkylene, phenyl, carboxyalkyl, sulfoalkyl, hydroxyalkyl,alkoxyalkyl, alkylamino groups, or heterocyclic nuclei. Combinations ofthese dyes may be used, if desired. In addition, supersensitizingaddenda which do not absorb visible light may be included, for instance,ascorbic acid derivatives, azaindenes, cadmium salts, andorganicsulfonic acids as described in McFall et al. U.S. Pat. No.2,933,390 and Jones et al. U.S. Pat. No. 2,937,089. The multilayerphotographic elements of the invention can be spectrally sensitized, andcan contain the filter layers described by Schwan et al. U.S. Pat.application Ser. No. 715,005 filed Mar. 21, 1968, now abandoned andcorresponding Belgian Pat. 729,204 of Aug. 28, 1969, and Schwan et al.continuation-in-part application Ser. No. 864,275 filed Sept. 29, 1969.

Spectral sensitizing dyes can be added to the emulsions of anyconvenient manner, such as by treating the emulsion with a solution of asensitizing dye in an organic solvent or the dye may be added in theform of a dispersion as described in Owens et al. British Pat. 1,154,781of June 11, 1969. For optimum results, the dye may either be added tothe emulsion as a final step or at some earlier stage.

The silver halide emulsions used in this invention can containspeed-increasing compounds such as polyalkylene glycols, cationicsurface active agents and thioethers of combinations of these asdescribed in Piper U.S. Pat. No. 2,886,437; Chechak U.S. Pat. No.3,046,134; Carroll et al. U.S. Pat. No. 2,944,900; and Goffe U.S. Pat.No. 3,294,540.

The converted-halide silver halide emulsions used in this invention canbe protected against the production of fog and can be stabilized againstloss of sensitivity during keeping. Suitable antifoggants andstabilizers, which can be used alone or in combination, include thethiazolium salts described in Staud U.S. Pat. No. 2,131,038 and AllenU.S. Pat. No. 2,694,716; the azaindenes described in Piper U.S. Pat. No.2,886,437 and Heimbach U.S. Pat. No. 2,444,605; the mercury saltsdescribed in Allen U.S. Pat. No. 2,728,663; the urazoles described inAnderson U.S. Pat. No. 3,287,135; the sulfocatechols described inKennard U.S. Pat. No. 3,236,652; the oximes described in carroll et al.British Pat. 623,448;

, aminophenols, 3-pyrazolidones, ascorbic acid and its derivatives,reductones and phenylenediamines, or combinations of developing agents.The developing agents can be in a silver halide emulsion and/or inanother suitable location in the photo graphic element. The developingagents can be added from suitable solvents or in the form of dispersionsas described in Yackel U.S. Pat. No. 2,592,368 and Dunn et al. FrenchPat. 1,505,778.

Silver halide emulsions useful in accordance with the invention can bedispersed in colloids that can be hardened by various organic orinorganic hardeners, alone or in combination, such as the aldehydes, andblocked aldehydes, ketones, carboxylic and carbonic acid derivatives,sulfonate esters sulfonyl halides and vinyl sulfones, active halogencompounds, epoxy compounds, aziridines, active olefins, isocyanates,carbodiimides, mixed function hardeners and polymeric hardeners such asoxidized polysaccharides, e.g., dialdehyde starch, ox-

yguargum, etc.

Photographic silver halide emulsions employed herein can contain variouscolloids alone or in combination as vehicles or binding agents. Suitablehydrophilic materials include both naturally occurring substances suchas proteins, for example, gelatin, gelatin derivatives, cellulosederivatives, polysaccharides such as dextran, gum arabic and the like;and synthetic polymeric substances such as water-soluble polyvinylcompounds, e.g., poly(vinylpyrrolidone) acrylamide polymers or othersynthetic polymeric compounds such as dispersed vinyl compounds in latexform, and particularly those which increase the dimensional stability ofthe photographic materials. Suitable synthetic polymers include thosedescribed, for example, in U.S. Pat. Nos. 3,142,568 of Nottorf, issuedJuly 28, 1964; 3,193,386 of White, issued July 6, 1965; 3,062,674 ofHouck, Smith and Yudelson, issued Nov. 6, 1962; 3,220,844 of Houck,Smith and Yudelson, issued Nov. 30, 1965; Ream and Fowler 3,287,289issued Nov. 22, 1966; and Dykstra U.S. Pat. No. 3,41 1,91 l;particularly effective are those water-insoluble polymers of alkylacrylates and methacrylates, acrylic acid, sulfoalkyl acrylates ormethacrylates, those which have cross-linking sites which facilitatehardening or curing and those having recurring sulfobetaine units asdescribed in Canadian Pat. 774,054.

Photographic silver halide emulsions in accordance with this inventioncan be used in photographic elements which contain antistatic orconducting layers, such as layers that comprise soluble salts, e.g.,chlorides, nitrates, etc., evaporated metal layers, ionic polymers suchas those described in Minsk U.S. Pat. Nos. 2,861,056 and 3,206,312 orinsoluble inorganic salts such as those described in Trevoy U.S. Pat.No. 3,428,451.

Photographic silver halide emulsions used in the invention can be coatedon a wide variety of supports. Typical supports include cellulosenitrate film, cellulose ester film, poly(vinyl acetal) film, polystyrenefilm, poly(ethylene terephthalate) film, polycarbonate film and relatedtilms or resinous materials, as well as glass, paper, metal and thelike. Typically, a flexible support is employed, especially a papersupport, which can be partially acetylated or coated with baryta and/oran alpha-olefin polymer, particularly a polymer of an alpha-olefincontaining two to 10 carbon atoms such as polyethylene, polypropylene,ethylenebutene copolymers and the like.

Photographic silver halide emulsions of the invention can containplasticizers and lubricants such as polyalcohols, e.g.,

glycerin and diols of the type described in Milton U.S. Pat. No.2,960,404; fatty acids or esters such as those described in Robijns U.S.Pat. No. 2,588,765 and Duane U.S. Pat. No. 3,121,060; and siliconeresins such as those described in Du- Pont British Pat. 955,061.

The converted-halide photographic emulsions useful herein can containsurfactants such as saponin, anionic compounds such as the alkyl arylsulfonates described in Baldsiefen U.S. Pat. No. 2,600,831 andamphoteric compounds such as those described in Ben-Ezra U.S. Pat. No.3,133,816.

Photographic elements containing emulsion layers as described herein cancontain matting agents such as starch, titanium dioxide, zinc oxide,silica polymeric beads including beads of the type described in Jelleyet a1. U.S. Pat. No. 2,992,101 and Lynn U.S. Pat. No. 2,701,245.

Silver halide emulsions described herein can be utilized in photographicelements which contain brightening agents including stilbene, triazine,oxazole and coumarin brightening agents. Water-soluble brighteningagents can be used such as those described in Albers et al. German Pat.972,067 and Mc- Fall et al. U.S. Pat. No. 2,933,390 or dispersions ofbrighteners can be used such as those described in Jansen German Pat.1,150,274 and Oetiker et al. U.S. Pat. No. 3,406,070.

Light-sensitive photographic emulsion layers hereof can be used inphotographic elements which contain light-absorbing materials and filterdyes such as those described in Sawdey U.S. Pat. No. 3,252,921; GasparU.S. Pat. No. 2,274,782; Carroll et al. U.S. Pat. No. 2,527,583 andVanCompen U.S. Pat. No. 2,956,879. If desired, the dyes can bemordanted, for example, as described in Milton and Jones U.S. Pat. No.3,282,699.

The sensitizing dyes (and other emulsion addenda) can be added to thephotographic emulsion from water solutions or suitable organic solventsolutions, for example with the procedure described in Collins et al.US. Pat. No. 3,342,605; 2,912,343; Owens et a1. U.S. Pat. No. 3,342,605;Audran U.S. Pat. No. 2,996,287 or Johnson et a1. U.S. Pat. No.3,425,835. The dyes can be dissolved separately or together, and theseparate or combined solutions can be added to a silver halide emulsion,or a silver halide emulsion layer can be bathed in the solution of dyeor dyes.

Photographic emulsions of this invention can be coated by variouscoating procedures including dip coating, air knife coating, curtaincoating, or extrusion coating using hoppers of the type described inBeguin U.S. Pat. No. 2,681,294. If desired, two or more layers may becoated simultaneously by the procedures described in Russell U.S. Pat.No. 2,761,791 and Wynn British Pat. 837,095.

The following examples are included for a further understanding of theinvention.

EXAMPLE 1 A light-sensitive silver chlorobromide gelatin emulsion isprepared which contains about mole percent chloride and about 90 molepercent bromide per mole of silver halide, using a technique similar tothat described in example 1 of Davey et al. U.S. Pat. No. 2,592,250issued Apr. 8, 1952, except no iodide salt is added. The coagulationwashing procedure, which is used to remove unwanted salts, is describedin example 1 of Yutzy et a1. U.S. Pat. No. 2,614,928 issued Oct. 21,1952. When the washing procedure has been completed, additional gelatinand water are added to adjust the gelatin concentration and the finalweight. The resulting light-sensitive silver chlorobromide emulsion istreated with sodium thiosulfate pentahydrate at a concentration of 20mg. per silver mole for the purpose of creating electron traps at thesurface of the silver halide grain. The sodium salt of 4-hydroxy-6-methyl-l,3,3a, 7-tetrazaindene, whose function is to slow theripening process and prevent further grain growth, is also added at aconcentration of 133 mg. per mole of silver. The emulsion is thenripened for 18 minutes at a temperature of 65 C. The resulting surfacesensitized silver halide grains have higher surface sensitivity to lightthan do the unsensitized silver halide grains, which have a highinternal native sensitivity.

EXAMPLE 2 A light-sensitive silver chlorobromide gelatin emulsion isprepared using the technique described in Davey et al. U.S. Pat. No.2,592,250, except no iodide salt is added. The following variations aremade. To a potassium chloride aqueous gelatin solution is added, at acontrolled rate of addition, silver nitrate which has been dissolved indistilled water. When all the silver nitrate solution has been added,potassium bromide, dissolved in distilled water, is added whilecontrolling the rate of addition. The resulting silver chlorobromidegelatin colloid is coagulation washed as described in example 1. Thesilver chlorobromide gelatin coagulum is adjusted to a desired gelatinconcentration and weight by the addition of an aqueous gelatin solution.The halide concentration of the resulting silver chlorobromidephotographic emulsion is about 10 mole percent chloride and about molepercent bromide per mole of silver halide. This internallylight-sensitive emulsion is then treated with an aqueous solution ofsodium thiosulfate pentahydrate (chemical sensitizer). An amount ofsolution is added in sufficient quantity to give a total dryconcentration of sodium thiosulfate pentahydrate of 9 mg. per mole ofsilver halide. An additional compound, the sodium salt of4-hydroxy-6-methyl-l,3,3a, 7-tetrazaindene, whose function is describedin example 1, as added at a silver halide molar concentration of 133 mg.This emulsion is then heated to 65 C. and held for a period of 20minutes and then rapidly cooled. The addition of the above chemicalsensitizer to this silver chlorobromide light-sensitive emulsion haschanged its lightsensitive characteristics from high internalsensitivity to a high surface sensitivity.

EXAMPLE 3 Samples of 2 layer light-sensitive materials (coatings d, eand f) are prepared. Layer 1, which is coated on a paper support coatedon both sides with polyethylene, comprises the silver chlorobromidegelatin emulsion of example 1 which has been spectrally sensitized tored light and coated at about 35 mg. of silver per square foot, about155 mg. of gelatin per square foot and about 35 mg. of the cyandye-forming color coupler 2-[a-(2,4-di-tert-amylphenoxy)butyramido]-4,6-dichloro-S-methylphenol per square foot. A second layer, a gelatinprotective layer, is coated over layer 1 at a coverage of about mg. ofgelatin per square foot. Coatings d, e and f, which contain chemicallysensitized converted-halide emulsions used in this invention, arecompared to control sample coatings a, b and c which are of the samestructure as coatings d, e and f, with the exception that coatings a, band c employ conventional negative silver chlorobromide gelatinemulsions of the type described by Trivelli and Smith Phot. 1., Vol.LXX- IX, pp. 330-338, May, 1939. The halide composition of the controllight-sensitive emulsions are about 10 percent chloride and about 90percent bromide per mole of silver halide. The control emulsions arechemically sensitized with 20 mg. per mole of silver of sodiumthiosulfate pentahydrate. Coatings a, b, c, d, e and f are each exposedto red light on an Eastman 1B Sensitometer and the latent imagesconverted into visible images using color process described in HannaU.S. Pat. No. 3,480,434 issued Nov. 25, 1969, example 1, columns 4 and5, in which the solutions are kept at a temperature of about 30 C.Samples of the coatings are developed for a duration of 2, 4 and 6minutes. Table 1 compares the relative speed, fog, and maximum densityvalues for the development times noted.

TABLE I Time 01' Relative Coating Development Speed Fog Dmu a (control)2' 100 0.10 2.02 12 (control) 4' 132 0.10 2.22 4 (control) 6' 159 0.122.20

d(invention) 2' 145 0.10 2.28 e (invention) 4 191 0.12 2.29 [(invention)6' 214 0.14 2.28

Table 1 shows that the elements of the invention have greaterdevelopability, higher maximum density, lower fog at the 4 and 6 minutedevelopment times, and are faster than the control coating The greaterdevelopability of the elements .of the invention is further illustratedby the fact that the control element must be developed for 6 minutes toprovide a sensitometric curve shape similar to the sensitometric curveof an element of the invention which is developed for 2 minutes. Resultsessentially similar to those of example 3 are obtained when theconverted-halide emulsion of example 2 is replaced with a similaremulsion which is chemically sensitized with a noble metal sensitizer,such as potassium chloroaurate; a labile selenium sensitizer such asdiethylselenide; a reduction sensitizer such as a stannous salt; apolyamine such as diethylene tn'amine or, a combination of sensitizerssuch as a noble metal together with a labile selenium compound and/or asulfur compound, such as the combination of potassium chloroaurate,sodium thiosulfate pentahydrate and N,N- dimethylselenourea.

EXAMPLE 4 Two samples of a multilayer, multicolor light-sensitivephotographic paper, coatings c and d, are prepared having the followingcomposition:

Layer 6-gelatin Layer --red-sensitive silver halide emulsion and aphenolic cyan coupler r Layer 4- gelatin Layer 3green-sensitive silverhalide emulsion containing a pyrazolone magenta coupler Layer 2-gelatinLayer 1blue-sensitive silver halide emulsion containing an acylacetanilide yellow coupler Paper support (both sides polyethylenecoated) Layer 1, the yellow dye-forming layer, contains thechemically-sensitized converted-halide silver chlorobromide gelatinphotographic emulsion described in example 2. Two other samples of amultilayer, multicolor light-sensitive photographic paper, controlcoatings a and b, are prepared just like coatings c and d, except that asilver chlorobromoiodide photographic gelatin emulsion of a type similarto that described by Glafkides, Photographic Chemistry, Vol. 1, pp.301-304, is substituted for the converted-halide silver halide emulsion.The halide composition of the photographic emulsion of coatings a and bis about 10 percent chloride, and 90 percent bromide. This emulsion ischemically sensitized by treatment with an aqueous sodium thiosulfatepentahydrate solution in a quantity sufficient to give a dry weightconcentration of 9 mg. sodium thiosulfate pentahydrate per mole ofsilver halide. Samples of these coatings are exposed to blue light on anEastman 1B Sensitometer and then processed as described in example 3.Coatings a and c are developed for 3 minutes and coatings b and d aredeveloped for 6 minutes. Table I1 compares the relative speed, fog andmaximum density of these coatings.

It should be noted that the coating 0, containing an emulsion of thisinvention, when developed for 3 minutes, exhibits greater speed andhigher maximum density than control coating a produces in the same 3minute development. Coating c also exhibits higher gamma than thecontrol coating a. Coating c of the invention, when developed for 3minutes, produces a curve of the same gamma and slightly lower maximumdensity than coating d of the invention, which is developed for 6minutes. Elements containing the silver chlorobromide emulsions of thisinvention exhibit greater developability than the control elementshaving conventional chemically sensitized silver chlorobromideemulsions.

EXAMPLE 5 A light-sensitive silver chlorobromoiodide gelatin emulsion isprepared using the technique described in Davey et al. U.S. Pat. No.2,592,250. The following steps are employed. To a potassium chlorideaqueous gelatin solution is added, at a controlled rate of addition,silver nitrate which has been dissolved in distilled water. When all thesilver nitrate has been added, potassium bromide and potassium iodide,dissolved in distilled water, are added while controlling the rate ofaddition. When all the potassium bromoiodide solution has been added,another potassium bromoiodide solution is added, again controlling therate of addition. The resulting silver chlorobromoiodide emulsion iscoagulation washed as in example and the gelatin concentration and finalweight is adjusted, and the emulsion is chemically sensitized asdescribed in example 2. The halide concentration of the resulting silverchlorobromoiodide photographic emulsion is about 12 mole percentchloride, about 87 mole percent bromide and about 1 mole percent iodideper mole of silver halide. This emulsion is substituted for the emulsionof the yellow dye-forming layer of coating 0 in example 4. This coating,and a sample of control coating a of example 4, are perforated and thendeveloped for 3 minutes as in example 4. Coating a of example 4,containing a conventional negative type emulsion, produces a yellowstain around the punch marks. The sample coating of this example,containing a converted-halide emulsion, produces no stain and remainswhite in the areas of the punches. A similar test is conducted oncoating 0 of example 4, and no stain is observed; the coating remainswhite in the areas of the punch marks. The photographic elements of thisinvention thus exhibit greater resistance to pressure sensitivity thancolorproducing photographic elements employing conventional negativesilver halide emulsions. Similar resistance to pressure sensitivity isobserved when the emulsion of coating c of example 4 is replaced with aconverted-halide silver halide emulsion chemically sensitized with anoble metal sensitizer, such as potassium chloroaurate; a labileselenium sensitizer such as diethylselenide; a reduction sensitizer suchas a stannous salt; a polyamine such as diethylene triamine or, acombination of sensitizers such as a noble metal together with a labileselenium compound and/or a sulfur compound, such as the com bination ofpotassium chloroaurate, sodium thiosulfate pentahydrate andN,N-dimethylselenourea.

EXAMPLE 6 A multicolor photographic element, element A, containing thechemically sensitized converted-halide silver halide emulsions employedin the invention is prepared as follows:

ELEMENT A Layer 6-gelatin overcoat coated at about mg. gelatin persquare foot Layer 5--a chemically sensitized converted-halide silverhalide gelatin emulsion of example 1, spectrally sensitized to redlight, is coated at a silver coverage of about 35 mg. per square foot,about mg. of gelatin per square foot and contains about 35 mg. persquare foot of the cyan dye-forming coupler2-[a-(2,4-di-tert-amyl-phenoxy)butyramido]-4,6-dichloro-S-methylphenolLayer 4-a gelatin layer coated at about 200 mg. gelatin per square footand containing about 65 mg. per square foot of the ultraviolet absorber2-(2-hydroxy-3,S-di-tert-amylphenyl)benzotriazole Layer 3-a chemicallysensitized converted-halide silver halide gelatin emulsion of example 1,spectrally sensitized to green light, is coated at a coverage of about45 mg. silver per square foot, about 200 mg. gelatin per square foot andabout 55 mg. per square foot of the magenta dyeforming couplerl-(2,4,6-trichlorophenyl)-3-[2-chloro-5 (a 4-hydroxy-3-tert.butylphenoxytetradecanoamido)anilinol--pyrazolone Layer 2a gelatin interlayer coatedat about 100 mg. gelatin per square foot Layer l-a chemically sensitizedconverted-halide silver halide gelatin emulsion of example 1, spectrallysensitive to blue light, coated at a silver coverage of about 50 mg. persquare foot and about 200 mg. gelatin per square foot, and containingabout 150 mg. per square foot of the yellow dye-forming couplera-[4-(4-benzyloxyphenyl-sulfonyl)-phenoxy]-a-pivalyl-2-chloro-5-[-y-(2,4-di-tertamylphenoxy)butyramido]-acetanilideSupport-coated on both sides with white TiO pigmented polyethyleneelectron bombarded to promote adhesion between the support and theoverlying hydrophilic colloid layers A control photographic element,element B, is prepared exactly like element A except that the chemicallysensitized converted-halide silver halide grains in each emulsion layerare replaced with conventional negative silver halide emulsions preparedas described by Trivelli and Smith Photo. 1., Vol. LXXlX, pp. 330-338,May, 1939, the halide of the silver halide consisting of about molepercent chloride and about 90 mole percent bromide, and chemicallysensitized with about mg. per mole of silver of sodium thiosulfatepentahydrate. Samples of elements A and B are then exposed anddeveloped, as described in example 3 for various development times. Therelative speeds (calculated at a reflection density of 1.0) and theminimum density (Dmin) and the maximum density (D- max) are shown intable 111 below:

TABLE 111 Develop- Blue ment Time Relative Element (min.) Speed DminDmax A (invention) 1 0.08 0.62 2 16.5 0.10 1.35 3 46 0.10 1.96 4 63 0.122.19 5 68 0.10 2.22 6 73 0.12 2.10

B (control) 2 0.09 0.92 4 60 0.11 1.84 6 100 0.12 2.36 B 112 0.13 2.4610 123 0.13 2.56 12 123 0.14 2.54

Dcvelop- Green ment Time Relative Element (min.) Speed Dmin Dmax A(invention) l 31 0.10 1.96

8 (control) 2 47 0.10 2.17 4 80 0.10 2.46 6 100 0.10 z.'4a 8 118 0.132.47 I0 129 0.11

Develop- Red ment Time Relative Element (min.) Speed Dmin Dmax A(invention) 1 83 0.10 2.36 2 102 0.10 2.12 3 0.10 2.23 4 132 0.12 2.25 5141 0.10 2.32 6 166 0.12 2.30

B (control) 2 45 0.07 2.42 4 76 0.10 2.51 6 100 0.10 2.50 8 0.12 2.53 10143 0.13 2.56 12 159 0.13 2.54

Table III shows the greater developability, higher speed and increasedmaximum density of photographic elements containing the chemicallysensitized converted-halide silver halide emulsions of this invention ascompared with the control element having conventional chemicallysensitized silver halide emulsions. Essentially similar results areobtained when the chemical sensitizer used in the emulsions of element Ais a noble metal sensitizer, such as potassium chloroaurate; a labileselenium sensitizer such as diethylselenide; a reduction sensitizer suchas a stannous salt; a polyamine such as diethylene triamine or, acombination of sensitizers such as a noble metal together with a labileselenium compound and/or a sulfur compound, such as the combination ofpotassium chloroaurate, sodium thiosulfate pentahydrate and N,N-dimethyl-selenourea, or when the halide of each emulsion contains about75 mole percent bromide, 20 mole percent chloride and 5 mole percentiodide.

EXAMPLE 7 Samples of elements A and B of example 6 are incubated for upto 28 weeks at a temperature of 20 C. and a relative humidity of 50percent. These coatings are then exposed and processed as described inexample 6. Table [V compares the change of shoulder density of theincubated coatings relative to the fresh processed coatings.

TABLE IV Element A (invention) Element B (control) Keeping ADM, ADM.ADmnx, ADM. ADmll, ADM. period cyan magenta yellow cyan magenta yellowFresh O. 00 0. 00 0. 00 0. 00 0.00 0.00 4 weeks -0. 03 0.00 O. 01 0. 04+0. 06 0. 01 8 weeks" 0. 00 0. 00 +0. 03 0. 01 0. 10 0. 03 12 weeks---0. 00 0. 04 +0.01 0. 07 +0.07 0. 02 16 weeks 0. 00 0. 02 0. O2 0. 07 +0.09 0. 05 20 weeks 0.04 +0.01 0.09 O.(l6 +0.13 0.08 24 weeks 0. 06 0. 05--0. 09 -O. 06 +0. 13 0. 08 28 weeks 0.05 -0. 10 0. 12 0.08 +0.14 -0.07

Table IV shows the high stability of element A of this invention througha period of 16 weeks before any major shifts become visible. The controlcoating, element B, has increased 0.10 in magenta density at the end of8 weeks and any resulting photographic prints would have an overall pinktone. Table V compares the stain increase of the incubated coatings (at20 C. and 50 percent relative humidity) when compared with the fresh.These data display the relative stability of both the cyan and magentalayers of both elements A and B. The yellow emulsion of element Bincreases rapidly in stain and by the end of 12 weeks has reached thepoint where it is no longer usable. The yellow layer of element A ofthis invention remains relatively stable. The growth of stain tends toshift the white areas of the print toward the dominant color densitychange, in this case toward the yellow. It should be pointed out that a0.02 minimum density shift is far more critical than a 0.10 densitychange in the shoulder. The human eye is much more sensitive to densitychanges in the minimum density areas than it is in the areas of highcolor saturation; however, a change such as that seen in the magentashoulder is perceivable and shifts the color balance toward the red.

TABLE V Element A (invention) Element B (control) Keeping Dmll Drniu.ADmln. ADmin. ADmln. rnin. period cyan magenta yellow cyan magentayellow The invention has been described in detail with particularreference to preferred embodiments thereof, but, it will be understoodthat variations and modifications can be effected within the spirit andscope of the invention.

I claim:

1. A light-sensitive photographic emulsion comprising convetted-halidesilver halide grains, the halide of said grains containing at least 50mole percent bromide and up to 10 mole percent iodide, any remaininghalide in said grains being chloride; the surface of said grains beingchemically sensitized; and, said emulsion containing a photographiccolor coupler.

2. A light-sensitive photographic emulsion comprising converted-halidesilver halide grains, the halide of said grains containing at least 80mole percent bromide and up to 5 mole percent iodide, any remaininghalide in said grains being chloride; the surface of said grains beingchemically sensitized; and, said emulsion containing a photographiccolor coupler.

3. A light-sensitive photographic emulsion comprising convetted-halidesilver halide grains, the halide of said grains containing at least 80mole percent bromide and up to 5 mole percent iodide, any remaininghalide in said grains being chloride; the surface of said grains beingchemically sensitized with at least one chemical sensitizer selectedfrom the group consisting of a sulfur sensitizer, a noble metalsensitizer, a reduction sensitizer and a selenium sensitizer; and, saidemulsion containing a photographic color coupler selected from the groupconsisting of an open-chain ketomethylene color coupler, a 5- pyrazolonecolor coupler, and a phenolic color coupler.

4. A light-sensitive photographic emulsion comprising converted-halidesilver chlorobromide grains dispersed in gelatin, the halide of saidgrains consisting essentially of about 10 mole percent chloride and 90mole percent bromide; the surface of said grains being chemicallysensitized with about 20 milligrams sodium thiosulfate pentahydrate permole of silver; and, said emulsion containing the phenolic color coupler2-[a-( 2,4-di-tert-amylphenoxy)butyramido]-4,6-dichloro-5- methylphenol.

5. A photographic element comprising a support having coated thereon atleast one light-sensitive photographic emulsion layer comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least 50 mole percent bromide and up to 10 mole percentiodide, any remaining halide being chloride; the surface of said grainsbeing chemically sensitized; and, said emulsion layer having aphotographic color coupler contiguous to said silver halide grains.

6. A photographic ele'ment comprising a support having coated thereon atleast one light-sensitive photographic emulsion layer comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least 80 mole percent bromide and up to 5 mole percentiodide, any remaining halide being chloride; the surface of said grainsbeing chemically senllsi sitized; and, said emulsion layer having aphotographic color coupler contiguous to said silver halide grains.

7. A photographic element comprising a support having coated thereon atleast one light-sensitive photographic emulsion layer comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least mole percent bromide and up to 5 mole percentiodide, any remaining halide being chloride; the surface of said grainsbeing chemically sensitized with at least one chemical sensitizerselected from the group consisting of a sulfur sensitizer, a noble metalsensitizer, a reduction sensitizer and a labile selenium sensitizer.

8. A photographic element comprising a support having coated thereon atleast three superposed hydrophilic colloid layers containinglight-sensitive silver halide grains, said layers being differentiallysensitive to red, green and blue radiation, said layers havingcontiguous to the silver halide thereof, respectively, cyan, magenta andyellow dye-fonning photographic color couplers; the silver halide grainsin at least one of said silver halide emulsions comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least 50 mole percent bromide and up to 10 mole percentiodide, any remaining halide being chloride, the surface of saidconverted-halide grains being chemically sensitized.

9. A photographic element comprising a support having coated thereon atleast three superposed hydrophilic colloid layers containinglight-sensitive silver halide grains, said layers being differentiallysensitive to red, green and blue radiation, said layers havingcontiguous to the silver halide thereof, respectively, cyan, magenta andyellow dye-forming photographic color couplers; the silver halide grainsin at least one of said silver halide emulsions comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least 80 mole percent bromide and up to 5 mole percentiodide, any remaining halide being chloride, the surface of saidconvertedhalide grains being chemically sensitized with a chemicalsensitizer from the group consisting of a sulfur sensitizer, a noblemetal sensitizer, a reduction sensitizer and a selenium sensitizer.

10. The photographic element as defined in claim 9 wherein saidphotographic color couplers are incorporated in the emulsion layers;said red-sensitive emulsion layer contains a phenolic cyan dye-formingphotographic color coupler; said green-sensitive emulsion layer containsa S-pyrazolone photographic color coupler; and, said blue-sensitiveemulsion layer contains an open-chain ketomethylene photographic colorcoupler.

11. A photographic element comprising a support having coated thereon atleast three superposed hydrophilic colloid layers containinglight-sensitive silver halide grains, said layers being differentiallysensitive to red, green and blue radiation, said layers havingincorporated therein, respectively, cyan, magenta and yellow dye-formingphotographic color couplers; the light-sensitive silver halide in eachof said layers comprising converted-halide silver halide grains, thehalide of said grains containing at least 50 mole percent bromide and upto 10 mole percent iodide, any remaining halide being chloride; and, thesurface of said grains being chemically sensitized.

12. A photographic element comprising a support having coated thereon atleast three superposed hydrophilic colloid layers containinglight-sensitive silver halide grains, said layers being differentiallysensitive to red, green and blue radiation, said layers havingincorporated therein, respectively, cyan, magenta and yellow dye-formingphotographic color couplers; the light-sensitive silver halide in eachof said layers comprising converted-halide silver halide grains, thehalide of said grains containing at least 80 mole percent bromide and upto 5 mole percent iodide, any remaining halide being chloride; and, thesurface of said grains being chemically sensitized with at least onechemical sensitizer selected from the group consisting of a sulfursensitizer, a noble metal sensitizer, a reduction sensitizer and aselenium sensitizer; said emulsion layers being arranged with thegreen-sensitive layer between the redand blue-sensitive emulsion layers,and the blue-sensitive emulsion layer being closest to the support.

13. A photographic element as defined in claim 12 having a hydrophiliccolloid layer containing an ultraviolet absorber between the greenandred-sensitive emulsion layers.

14. A photographic element comprising a paper support having coatedthereon, in the order given:

a blue sensitive silver halide emulsion coated at a silver coverage ofabout 35 milligrams silver per square foot and about 155 milligramsgelatin per square foot, said layer containing about 35 milligrams persquare foot of the cyan dye-forming couplera-[4-(4-benzyloxy-phenylsulfonyl )-phenoxy ]-a-pivalyl-2-chloro-5-['y-(2,4-ditert-amylphenoxy)butyramido]-acetanilide;

a gelatin interlayer;

a green-sensitive silver halide emulsion coated at about 35 milligramssilver per square foot and about 155 milligrams gelatin per square foot,

said layer containing about 35 milligrams per square foot of the magentadye-forming coupler l-(2,4,6-trichlorophenyl)-3-[2-chloro5(a-4-hydroxy-3-tert.butylphenoxy tetradecanoamido)-anilino]-5-pyrazolone;

a galatin interlayer containing about 65 mg. per square foot of theultraviolet absorber 2-( 2-hydroxy-3,S-di-tert-amylphenyl)benzotriazole;

a red-sensitive gelatin silver halide emulsion coated at about 35milligrams silver per square foot and about 155 milligrams gelatin persquare foot, said layer containing about 35 milligrams per square footof the cyan dye-forming coupler2-[a-(2,4-di-tert-amylphenoxy)butyramido]-4,6- dichloro-S-methylphenol;and, a gelatin overcoating; each of said emulsion layers consistingessentially of converted-halide silver halide grains, the halide of saidgrains containing about mole percent chloride and about 90 mole percentbromide.

15. A process for providing color images in an exposed photographicelement comprising a support having coated thereon a light-sensitivephotographic emulsion comprising converted-halide silver halide grains,the halide of said grains containing at least 50 mole percent bromideand up to 10 mole percent iodide, any remaining halide being chloride;the surface of said grains being chemically sensitized; and, said silverhalide grains having contiguous thereto a photographic color coupler;which comprises: developing said exposed photographic element with anaromatic primary amino color developing agent which reacts with saidcolor coupler to form a dye.

16. A process for providing color images in an exposed photographicelement comprising a support having coated thereon a light-sensitivephotographic emulsion comprising converted-halide silver halide grains,the halide of said grains containing at least 80 mole percent bromideand up to 5 mole percent iodide, any remaining halide being chloride;the surface of said grains being chemically sensitized with a chemicalsensitizer selected from the group consisting of a sulfur sensitizer, anoble metal sensitizer, a reduction sensitizer and a seleniumsensitizer; and, said silver halide grains having contiguous thereto aphotographic color coupler selected from the group consisting of aS-pyrazolone, a phenolic and an open-chain ketomethylene photographiccolor coupler; which comprises:

developing said exposed photographic element with a pphenylenediaminecolor developing agent which reacts with said color coupler to form adye; and,

removing silver halide and silver image from said element.

17. A process for providing color images in an exposed photographicelement comprising a support having coated thereon at least threesuperposed hydrophilic colloid layers containing light-sensitive silverhalide grains, said layers being differentially sensitive to red, greenand blue radiation, said layers having incorporated therein,respectivelp, cyan, magenta and yellow dye-forming photographic colorcouplers; the light-sensitive silver halide in each of said layerscomprising converted-halide silver halide grains, the halide of saidgrains containing at least 50 mole percent bromide and up to 10 molepercent iodide, any remainin halide being celoride; and, the surface ofsaid grains being c emically sensitized; which comprises:

developing said exposed photographic element with an aromatic primaryamino color developing agent which reacts with said color coupler toform a dye; and,

removing silver halide and silver image by fixing and bleaching.

18. A process for providing color images in an exposed photographicelement comprising a support having coated thereon at least threesuperposed hydrophilic colloid layers containing light-sensitive silverhalide grains, said layers being differentially sensitive to red, greenand blue radiation, said layers having incorporated therein,respectively, cyan, magenta and yellow dyeforming photographic colorcouplers; the light-sensitive silver halide in each of said layerscomprising converted-halide silver halide grains, the halide of saidgrains containing at least mole percent bromide and up to 5 mole percentiodide, any remaining halide being chloride; and, the surface of saidgrains being chemically sensitized with at least one chemicalsensitizer; selected from the group consisting of a sulfur sensitizer, anoble metal sensitizer, a reduction sensitizer and a seleniumsensitizer; said emulsion layers being arranged with the green-sensitivelayer between the redand blue-sensitive emulsion layers, and theblue-sensitive emulsion layer being closest to the support; whichcomprises:

developing said exposed photographic element with an aromatic primaryamino color developing agent which reacts with said color coupler toform a dye; and,

removing silver halide and silver image from said element by fixing andbleaching.

19. A light-sensitive photographic emulsion as defined in claim 3wherein said chemical sensitizer is selected from a sulfur sensitizerand a selenium sensitizer.

20. A light-sensitive photographic element as defined in claim 7 whereinsaid chemical sensitizer is selected from a sulfur sensitizer and aselenium sensitizer.

21. A light-sensitive photographic element as defined in claim 9 whereinsaid chemical sensitizer is selected from a sulfur sensitizer and aselenium sensitizer.

22. A light-sensitive photographic element as defined in claim 12wherein said chemical sensitizer is selected from a sulfur sensitizerand a selenium sensitizer.

23. A process for providing color images as defined in claim 16 whereinsaid chemical sensitizer is selected from a sulfur sensitizer and aselenium sensitizer.

24. A process for providing color images as defined in claim 18 whereinsaid chemical sensitizer is selected from a sulfur sensitizer and aselenium sensitizer.

Patent No.

Inventor(s) 3,622,318 Dated November 23, 1971 Francis J. Evans It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 2, line 1, "and" should read said line 51, after "Useful" insertsilver column 3, line 26, "1,547,944" should read 1,574,944 line 45,after "issued" insert June column 4, line 31, "2,046,129" should read--3,046,l29 column 7, line 37, cancel "3,342,605; "5 column 8, line 30,"as" should read is line 47, "tert" should read tert column 10, line 74,"tert" should read tert column 11, line 23, "Support-coated" should readupport--paper coated column 13, line 60 "tert" should read tert Signedand sealed this 12th day of December 1972.

(SEAL) Attest:

ROBERT GOTTSCHALK EDWARD M.FLETCHER,JR.

Commissioner of Patents Attesting Officer RM PO-105U (10-69) USCOMM-DC00376-5 09 U S, GOVERNMINT FH NTlNG OFFICE I "9 O-35-334

2. A light-sensitive photographic emulsion comprising converted-halidesilver halide grains, the halide of said grains containing at least 80mole percent bromide and up to 5 mole percent iodide, any remaininghalide in said grains being chloride; the surface of said grains beingchemically sensitized; and, said emulsion containing a photographiccolor coupler.
 3. A light-sensitive photographic emulsion comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least 80 mole percent bromide and up to 5 mole percentiodide, any remaining halide in said grains being chloride; the surfaceof said grains being chemically sensitized with at least one chemicalsensitizer selected from the group consisting of a sulfur sensitizer, anoble metal sensitizer, a reduction sensitizer and a seleniumsensitizer; and, said emulsion containing a photographic color couplerselected from the group consisting of an open-chain ketomethylene colorcoupler, a 5-pyrazolone color coupler, and a phenolic color coupler. 4.A light-sensitive photographic emulsion comprising converted-halidesilver chlorobromide grains dispersed in gelatin, the halide of saidgrains consisting essentially of about 10 mole percent chloride and 90mole percent bromide; the surface of said grains being chemicallysensitized with about 20 milligrams sodium thiosulfate pentahydrate permole of silver; and, said emulsion containing the phenolic color coupler2-( Alpha -(2,4-di-tert-amylphenoxy)butyramido)-4,6-dichloro-5-methylphenol.
 5. Aphotographic element comprising a support having coated thereon at leastone light-sensitive photographic emulsion layer comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least 50 mole percent bromide and up to 10 mole percentiodide, any remaining halide being chloride; the surface of said grainsbeing chemically sensitized; and, said emulsion layer having aphotographic color coupler contiguous to said silver halide grains.
 6. Aphotographic element comprising a support having coated thereon at leastone light-sensitive photographic emulsion layer comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least 80 mole percent bromide and up to 5 mole percentiodide, any remaining halide being chloride; the surface of said grainsbeing chemically sensitized; and, said emulsion layer having aphotographic color coupler contiguous to said silver halide grains.
 7. Aphotographic element comprising a support having coated thereon at leastone light-sensitive photographic emulsion layer comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least 80 mole percent bromide and up to 5 mole percentiodide, any remaining halide being chloride; the surface of said grainsbeing chemically sensitized with at least one chemical sensitizerselected from the group consisting of a sulfur sensitizer, a noble metalsensitizer, a reduction sensitizer and a labile selenium sensitizer. 8.A photographic element comprising a support having coated thereon atleast three superposed hydrophilic colloid layers containinglight-sensitive silver halide grains, said layers being differentiallysensitive to red, green and blue radiation, said layers havingcontiguous to the silver halide thereof, respectively, cyan, magenta andyellow dye-forming photographic color couplers; the silver halide grainsin at least one of said silver halide emulsions comprisingconverted-halide silver halide grains, the halide of said grainscontaining at least 50 mole percent bromide and up to 10 mole percentiodide, any remaining halide being chloride, the surface of saidconverted-halide grains being chemically sensitized.
 9. A photographicelement comprising a support having coated thereon at least threesuperposed hydrophilic colloid layers containing light-sensitive silverhalide grains, said layers being differentially sensitive to red, greenand blue radiation, said layers having contiguous to the silver halidethereof, respectively, cyan, magenta and yellow dye-forming photographiccolor couplers; the silver halide grains in at least one of said silverhalide eMulsions comprising converted-halide silver halide grains, thehalide of said grains containing at least 80 mole percent bromide and upto 5 mole percent iodide, any remaining halide being chloride, thesurface of said converted-halide grains being chemically sensitized witha chemical sensitizer from the group consisting of a sulfur sensitizer,a noble metal sensitizer, a reduction sensitizer and a seleniumsensitizer.
 10. The photographic element as defined in claim 9 whereinsaid photographic color couplers are incorporated in the emulsionlayers; said red-sensitive emulsion layer contains a phenolic cyandye-forming photographic color coupler; said green-sensitive emulsionlayer contains a 5-pyrazolone photographic color coupler; and, saidblue-sensitive emulsion layer contains an open-chain ketomethylenephotographic color coupler.
 11. A photographic element comprising asupport having coated thereon at least three superposed hydrophiliccolloid layers containing light-sensitive silver halide grains, saidlayers being differentially sensitive to red, green and blue radiation,said layers having incorporated therein, respectively, cyan, magenta andyellow dye-forming photographic color couplers; the light-sensitivesilver halide in each of said layers comprising converted-halide silverhalide grains, the halide of said grains containing at least 50 molepercent bromide and up to 10 mole percent iodide, any remaining halidebeing chloride; and, the surface of said grains being chemicallysensitized.
 12. A photographic element comprising a support havingcoated thereon at least three superposed hydrophilic colloid layerscontaining light-sensitive silver halide grains, said layers beingdifferentially sensitive to red, green and blue radiation, said layershaving incorporated therein, respectively, cyan, magenta and yellowdye-forming photographic color couplers; the light-sensitive silverhalide in each of said layers comprising converted-halide silver halidegrains, the halide of said grains containing at least 80 mole percentbromide and up to 5 mole percent iodide, any remaining halide beingchloride; and, the surface of said grains being chemically sensitizedwith at least one chemical sensitizer selected from the group consistingof a sulfur sensitizer, a noble metal sensitizer, a reduction sensitizerand a selenium sensitizer; said emulsion layers being arranged with thegreen-sensitive layer between the red- and blue-sensitive emulsionlayers, and the blue-sensitive emulsion layer being closest to thesupport.
 13. A photographic element as defined in claim 12 having ahydrophilic colloid layer containing an ultraviolet absorber between thegreen- and red-sensitive emulsion layers.
 14. A photographic elementcomprising a paper support having coated thereon, in the order given: ablue sensitive silver halide emulsion coated at a silver coverage ofabout 35 milligrams silver per square foot and about 155 milligramsgelatin per square foot, said layer containing about 35 milligrams persquare foot of the cyan dye-forming coupler Alpha-(4-(4-benzyloxy-phenylsulfonyl)-phenoxy)- Alpha -pivalyl-2-chloro-5 (gamma -(2,4-di-tert-amylphenoy)butyramido)-acetanilide; a gelatininterlayer; a green-sensitive silver halide emulsion coated at about 35milligrams silver per square foot and about 155 milligrams gelatin persquare foot, said layer containing about 35 milligrams per square footof the magenta dye-forming coupler1-(2,4,6-trichlorophenyl)-3-(2-chloro-5( Alpha - 4-hydroxy-3-tert.butylphenoxy tetradecanoamido)-anilino)-5-pyrazolone; agelatin interlayer containing about 65 mg. per square foot of theultraviolet absorber 2-(2-hydroxy-3,5-di-tert-amyl-phenyl)benzotriazoLe;a red-sensitive gelatin silver halide emulsion coated at about 35milligrams silver per square foot and about 155 milligrams gelatin persquare foot, said layer containing about 35 milligrams per square footof the cyan dye-forming coupler 2-( Alpha-(2,4-di-tert-amylphenoxy)butyramido)-4,6-dichloro-5-methylphenol; and,a gelatin overcoating; each of said emulsion layers consistingessentially of converted-halide silver halide grains, the halide of saidgrains containing about 10 mole percent chloride and about 90 molepercent bromide.
 15. A process for providing color images in an exposedphotographic element comprising a support having coated thereon alight-sensitive photographic emulsion comprising converted-halide silverhalide grains, the halide of said grains containing at least 50 molepercent bromide and up to 10 mole percent iodide, any remaining halidebeing chloride; the surface of said grains being chemically sensitized;and, said silver halide grains having contiguous thereto a photographiccolor coupler; which comprises: developing said exposed photographicelement with an aromatic primary amino color developing agent whichreacts with said color coupler to form a dye.
 16. A process forproviding color images in an exposed photographic element comprising asupport having coated thereon a light-sensitive photographic emulsioncomprising converted-halide silver halide grains, the halide of saidgrains containing at least 80 mole percent bromide and up to 5 molepercent iodide, any remaining halide being chloride; the surface of saidgrains being chemically sensitized with a chemical sensitizer selectedfrom the group consisting of a sulfur sensitizer, a noble metalsensitizer, a reduction sensitizer and a selenium sensitizer; and, saidsilver halide grains having contiguous thereto a photographic colorcoupler selected from the group consisting of a 5-pyrazolone, a phenolicand an open-chain ketomethylene photographic color coupler; whichcomprises: developing said exposed photographic element with ap-phenylenediamine color developing agent which reacts with said colorcoupler to form a dye; and, removing silver halide and silver image fromsaid element.
 17. A process for providing color images in an exposedphotographic element comprising a support having coated thereon at leastthree superposed hydrophilic colloid layers containing light-sensitivesilver halide grains, said layers being differentially sensitive to red,green and blue radiation, said layers having incorporated therein,respectively, cyan, magenta and yellow dye-forming photographic colorcouplers; the light-sensitive silver halide in each of said layerscomprising converted-halide silver halide grains, the halide of saidgrains containing at least 50 mole percent bromide and up to 10 molepercent iodide, any remaining halide being chloride; and, the surface ofsaid grains being chemically sensitized; which comprises: developingsaid exposed photographic element with an aromatic primary amino colordeveloping agent which reacts with said color coupler to form a dye;and, removing silver halide and silver image by fixing and bleaching.18. A process for providing color images in an exposed photographicelement comprising a support having coated thereon at least threesuperposed hydrophilic colloid layers containing light-sensitive silverhalide grains, said layers being differentially sensitive to red, greenand blue radiation, said layers having incorporated therein,respectively, cyan, magenta and yellow dye-forming photographic colorcouplers; the light-sensitive silver halide in each of said layerscomprising converted-halide silver halide grains, the halide of saidgrains containing at least 80 mole percent bromide and up to 5 molepercent iodide, any remaining halide beIng chloride; and, the surface ofsaid grains being chemically sensitized with at least one chemicalsensitizer; selected from the group consisting of a sulfur sensitizer, anoble metal sensitizer, a reduction sensitizer and a seleniumsensitizer; said emulsion layers being arranged with the green-sensitivelayer between the red- and blue-sensitive emulsion layers, and theblue-sensitive emulsion layer being closest to the support; whichcomprises: developing said exposed photographic element with an aromaticprimary amino color developing agent which reacts with said colorcoupler to form a dye; and, removing silver halide and silver image fromsaid element by fixing and bleaching.
 19. A light-sensitive photographicemulsion as defined in claim 3 wherein said chemical sensitizer isselected from a sulfur sensitizer and a selenium sensitizer.
 20. Alight-sensitive photographic element as defined in claim 7 wherein saidchemical sensitizer is selected from a sulfur sensitizer and a seleniumsensitizer.
 21. A light-sensitive photographic element as defined inclaim 9 wherein said chemical sensitizer is selected from a sulfursensitizer and a selenium sensitizer.
 22. A light-sensitive photographicelement as defined in claim 12 wherein said chemical sensitizer isselected from a sulfur sensitizer and a selenium sensitizer.
 23. Aprocess for providing color images as defined in claim 16 wherein saidchemical sensitizer is selected from a sulfur sensitizer and a seleniumsensitizer.
 24. A process for providing color images as defined in claim18 wherein said chemical sensitizer is selected from a sulfur sensitizerand a selenium sensitizer.